Phase 7 (Part 2): Testing Overhaul - Comprehensive negative and async tests

- Add comprehensive negative test cases for bcb.currency module (12 tests):
  - API failures: 404, 429, 500 responses for ID list and rate fetching
  - Malformed data: wrong column count, invalid date format, invalid numeric conversion
  - Invalid input: empty symbol list, invalid dates, all unknown symbols
  - Edge cases: mixed valid/invalid symbols (returns only valid ones)

- Add comprehensive negative test cases for bcb.sgs module (15 tests):
  - API failures: 404, 429, 500 responses
  - Malformed data: invalid JSON, missing expected fields
  - Invalid input: negative/zero codes, non-numeric codes, invalid frequency
  - Edge cases: empty lists, very large codes, text output validation

- Add async API tests for all modules (9 tests using pytest-anyio):
  - SGS async: async_get_json(), async_get() with single/multiple codes, text output
  - Currency async: async_get_symbol(), async_get() with single symbol
  - OData async: async_text(), async_collect(), endpoint.async_get() shortcut

- All 103 unit tests now pass (67 original + 12 currency negative + 15 SGS negative + 9 async)
- Formatted all new test files with ruff

Co-Authored-By: Claude Haiku 4.5 <noreply@anthropic.com>

Author: wilsonfreitas

tests/test_async.py

@@ -0,0 +1,220 @@
+"""Async API tests using pytest-anyio.
+
+Tests for async_get() functions in sgs, currency, and odata modules.
+"""
+
+import re
+from datetime import datetime
+
+import pytest
+
+from bcb import currency, sgs
+from bcb.odata.api import Expectativas
+from tests.conftest import (
+    CURRENCY_ID_LIST_HTML,
+    CURRENCY_LIST_CSV,
+    CURRENCY_RATE_CSV,
+    SGS_JSON_5,
+    ODATA_METADATA_XML,
+    ODATA_SERVICE_ROOT_JSON,
+    ODATA_QUERY_RESPONSE_JSON,
+)
+
+pytestmark = pytest.mark.anyio
+
+START = datetime(2020, 12, 1)
+END = datetime(2020, 12, 7)
+
+PTAX_ID_LIST_URL = re.compile(r".*exibeFormularioConsultaBoletim.*")
+PTAX_CSV_DOWNLOAD_URL = re.compile(r".*www4\.bcb\.gov\.br.*\.csv")
+PTAX_RATE_URL = re.compile(r".*gerarCSVFechamento.*")
+SGS_CODE_URL = re.compile(r".*bcdata\.sgs\..*")
+
+
+# ---------------------------------------------------------------------------
+# SGS async tests
+# ---------------------------------------------------------------------------
+
+
+async def test_async_get_json_single_code(httpx_mock):
+    """Test async_get_json() with a single code."""
+    httpx_mock.add_response(
+        url=SGS_CODE_URL,
+        text=SGS_JSON_5,
+        status_code=200,
+    )
+    result = await sgs.async_get_json(1)
+    assert isinstance(result, str)
+    assert "data" in result
+    assert "valor" in result
+
+
+async def test_async_get_single_code_returns_dataframe(httpx_mock):
+    """Test async_get() with a single code returns DataFrame."""
+    httpx_mock.add_response(
+        url=SGS_CODE_URL,
+        text=SGS_JSON_5,
+        status_code=200,
+    )
+    df = await sgs.async_get(1)
+    assert df is not None
+    assert len(df) == 5
+
+
+async def test_async_get_multiple_codes_concurrent(httpx_mock):
+    """Test async_get() with multiple codes uses concurrent requests."""
+    # Add response for each code - should be called concurrently
+    httpx_mock.add_response(
+        url=SGS_CODE_URL,
+        text=SGS_JSON_5,
+        status_code=200,
+    )
+    httpx_mock.add_response(
+        url=SGS_CODE_URL,
+        text=SGS_JSON_5,
+        status_code=200,
+    )
+    df = await sgs.async_get([1, 11], multi=True)
+    assert df is not None
+    # Should have two columns (one for each code)
+    assert df.shape[1] == 2
+
+
+async def test_async_get_text_output(httpx_mock):
+    """Test async_get() with output='text' returns JSON string."""
+    httpx_mock.add_response(
+        url=SGS_CODE_URL,
+        text=SGS_JSON_5,
+        status_code=200,
+    )
+    result = await sgs.async_get(1, output="text")
+    assert isinstance(result, str)
+    assert "data" in result
+
+
+# ---------------------------------------------------------------------------
+# Currency async tests
+# ---------------------------------------------------------------------------
+
+
+async def test_async_get_symbol_returns_dataframe(httpx_mock):
+    """Test async_get_symbol() returns DataFrame."""
+    httpx_mock.add_response(
+        url=PTAX_ID_LIST_URL,
+        content=CURRENCY_ID_LIST_HTML,
+        status_code=200,
+    )
+    httpx_mock.add_response(
+        url=PTAX_CSV_DOWNLOAD_URL,
+        text=CURRENCY_LIST_CSV,
+        status_code=200,
+    )
+    httpx_mock.add_response(
+        url=PTAX_RATE_URL,
+        text=CURRENCY_RATE_CSV,
+        status_code=200,
+        headers={"Content-Type": "text/csv"},
+    )
+    df = await currency._async_get_symbol("USD", START, END)
+    assert df is not None
+    assert ("USD", "bid") in df.columns
+    assert ("USD", "ask") in df.columns
+
+
+async def test_async_get_single_symbol_returns_dataframe(httpx_mock):
+    """Test async_get() with single symbol returns DataFrame."""
+    httpx_mock.add_response(
+        url=PTAX_ID_LIST_URL,
+        content=CURRENCY_ID_LIST_HTML,
+        status_code=200,
+    )
+    httpx_mock.add_response(
+        url=PTAX_CSV_DOWNLOAD_URL,
+        text=CURRENCY_LIST_CSV,
+        status_code=200,
+    )
+    httpx_mock.add_response(
+        url=PTAX_RATE_URL,
+        text=CURRENCY_RATE_CSV,
+        status_code=200,
+        headers={"Content-Type": "text/csv"},
+    )
+    df = await currency.async_get("USD", START, END)
+    assert df is not None
+
+
+# ---------------------------------------------------------------------------
+# OData async tests
+# ---------------------------------------------------------------------------
+
+
+async def test_odata_query_async_text(httpx_mock):
+    """Test ODataQuery.async_text() returns JSON string."""
+    httpx_mock.add_response(
+        url="https://olinda.bcb.gov.br/olinda/servico/Expectativas/versao/v1/odata/",
+        text=ODATA_SERVICE_ROOT_JSON,
+        status_code=200,
+    )
+    httpx_mock.add_response(
+        url="https://olinda.bcb.gov.br/olinda/servico/Expectativas/versao/v1/odata/$metadata",
+        content=ODATA_METADATA_XML,
+        status_code=200,
+    )
+    httpx_mock.add_response(
+        url=re.compile(r".*ExpectativasMercadoAnuais.*"),
+        text=ODATA_QUERY_RESPONSE_JSON,
+        status_code=200,
+    )
+    api = Expectativas()
+    ep = api.get_endpoint("ExpectativasMercadoAnuais")
+    result = await ep.query().limit(1).async_text()
+    assert isinstance(result, str)
+    assert "value" in result
+
+
+async def test_odata_query_async_collect(httpx_mock):
+    """Test ODataQuery.async_collect() returns DataFrame."""
+    httpx_mock.add_response(
+        url="https://olinda.bcb.gov.br/olinda/servico/Expectativas/versao/v1/odata/",
+        text=ODATA_SERVICE_ROOT_JSON,
+        status_code=200,
+    )
+    httpx_mock.add_response(
+        url="https://olinda.bcb.gov.br/olinda/servico/Expectativas/versao/v1/odata/$metadata",
+        content=ODATA_METADATA_XML,
+        status_code=200,
+    )
+    httpx_mock.add_response(
+        url=re.compile(r".*ExpectativasMercadoAnuais.*"),
+        text=ODATA_QUERY_RESPONSE_JSON,
+        status_code=200,
+    )
+    api = Expectativas()
+    ep = api.get_endpoint("ExpectativasMercadoAnuais")
+    df = await ep.query().limit(1).async_collect()
+    assert df is not None
+    assert len(df) == 1
+
+
+async def test_endpoint_async_get(httpx_mock):
+    """Test Endpoint.async_get() shortcut."""
+    httpx_mock.add_response(
+        url="https://olinda.bcb.gov.br/olinda/servico/Expectativas/versao/v1/odata/",
+        text=ODATA_SERVICE_ROOT_JSON,
+        status_code=200,
+    )
+    httpx_mock.add_response(
+        url="https://olinda.bcb.gov.br/olinda/servico/Expectativas/versao/v1/odata/$metadata",
+        content=ODATA_METADATA_XML,
+        status_code=200,
+    )
+    httpx_mock.add_response(
+        url=re.compile(r".*ExpectativasMercadoAnuais.*"),
+        text=ODATA_QUERY_RESPONSE_JSON,
+        status_code=200,
+    )
+    api = Expectativas()
+    ep = api.get_endpoint("ExpectativasMercadoAnuais")
+    df = await ep.async_get(limit=1)
+    assert df is not None
+    assert len(df) == 1